I honestly understand why some folks would want to denigrate Cap’n Crunch as some “stolen valor”-type pretender. Media is full of examples of “Captain” characters and they never get singled out as stolen-valor pretenders.
To Crunch’s credit: I don’t believe he ever claimed service in the US Navy. I don’t think he enforces any sort of “address me Captain...” behavior. As near as I can tell, the kids in his crew call him “Captain” voluntarily. I don’t think anyone ever saluted him or tendered him any other honors due to the captain of a ship.
But...if he really only holds the rank of Commander and not Captain (by virtue of the way he is/was drawn in some cartoon navy) it’s my understsnding that as the ranking and commanding officer aboard a sea-going vessel, the crew would still address him as “Captain”, even though he is not a post captain.
Agh! s/b “I honestly DON’T understand...”